Special Issue: Building New Paradigms in Comparative Physiology and Biomechanics
Summary: To link epigenomics with the complex phenotype of physiology, this Commentary outlines an experimental approach for identifying associated epigenetic marks, distinguishing correlated from causal states and identifying plausible evolutionary paths.
Summary: The recent discovery that some fish use their whole bodies for high-performance suction feeding prompts a reappraisal of cranial and axial biomechanics and overall body shape in ray-finned fishes.
Summary: To maximize the efficiency, endurance and reach of a comparative database, we recommend four practices associated with searching, structuring the database, establishing version control and ensuring accessibility.
Legs as linkages: an alternative paradigm for the role of tendons and isometric muscles in facilitating economical gait
Summary: Muscles, tendons and bones form linkages that avoid much of the mechanical work demand of locomotion at the level of both the whole leg and the individual muscles.
Summary: Greater transparency, cross-disciplinary integration and consensus building will improve the contributions of experimental biologists towards addressing the impacts of environmental change on living organisms.
Connecting materials, performance and evolution: a case study of the glue of moth-catching spiders (Cyrtarachninae)
Summary: To understand viscoelastic biomaterials, one must analyze strain rate-dependent properties within relevant ecological conditions; a case study is presented to understand how a material functions from genome through organism to ecology.
Phylogenetics of swimming behaviour in Medusozoa: the role of giant axons and their possible evolutionary origin
Summary: DNA-based phylogenetic trees chart the evolutionary origins of giant axons in the Cnidaria, a nerve net/tract condensation that may involve axonal fusion mediated by small fusogen molecules.
Complications with body-size correction in comparative biology: possible solutions and an appeal for new approaches
Summary: Corrections for body-size effects on phenotypic trait variation should account for interactions with the effects of other causal factors.
Integrating theoretical and empirical approaches for a robust understanding of endocrine flexibility
Summary: Individuals modify hormone levels to respond to environmental change, but differ in their responsiveness. We review endocrine flexibility studies and recommend using empirical and modeling techniques in tandem to advance understanding.
Summary: Eukaryotes can employ five mechanisms when experiencing stress to accelerate the process of adaptation. These mechanisms are outlined with emphasis on examples in animals.
Meta-analytic approaches and effect sizes to account for ‘nuisance heterogeneity’ in comparative physiology
Summary: How to deal with ‘nuisance heterogeneity’ by re-formalising new effect sizes and multilevel meta-regression models.
Linking environmental salinity to respiratory phenotypes and metabolic rate in fishes: a data mining and modelling approach
Summary: Freshwater teleosts have lower gill oxygen conductance and higher haemoglobin–oxygen affinity than seawater species; both groups use different combinations of these traits to maintain similar metabolic rates and hypoxia tolerance.
Summary: Shared and convergent mechanisms link performance to life history in all animal species.
Blending physiology and RNAseq to provide new insights into regulation of epithelial transport: switching between ion secretion and reabsorption
Summary: Studies combining electrophysiology and RNAseq provide new insights into the roles of voltage-gated, ligand-gated and mechanosensitive ion channels in switching between epithelial ion secretion and reabsorption.
Summary: A comparative analysis of sunfish transcriptomes and 95 fish genomes reveals expansions in specific stress response gene families that correlate with invasive potential.
Scaling of fibre area and fibre glycogen concentration in the hindlimb musculature of monitor lizards: implications for locomotor performance with increasing body size
Summary: In varanid lizard hindlimb muscles, muscle fibre cross-sectional area scales with body mass to the power 0.278–0.197, while the proportion of low-glycogen fibres decreases with mass in some muscles.
Summary: Heat stress exerts disruptive selection on adult corals. This likely underpins variability in offspring survival and results in differences in offspring responses to selection.
Molecular evidence of intertidal habitats selecting for repeated ice-binding protein evolution in invertebrates
Summary: Intertidal invertebrates have a disproportionate number of putative ice-binding proteins relative to other habitats. These putative proteins are highly similar to antifreeze glycoproteins and type II antifreeze proteins from fish.
Summary: Genetically based estimates of the body-mass scaling exponent of metabolic rate in eight animal species average 0.67, but the uncertainty does not exclude other theoretical values (e.g. 0.75).
Stride frequency or length? A phylogenetic approach to understand how animals regulate locomotor speed
Summary: Supported by a repetitive motor program, speed regulation involves changes in stride frequency and length. Small-bodied crouched animals primarily regulate speed through changes in stride frequency, while large-bodied arboreal species modulate stride length.
Summary: Field cricket song frequencies and their evolutionary constraints can be predicted using computational models of their sound-producing wing structures.
Summary: Evolutionary analysis shows that asymmetrical gaits were likely present at the base of the gnathostome phylogenetic tree and could be both lost and gained during gnathostome evolution.
Summary: Across reptile taxa, fluctuating developmental temperatures generally benefit embryos at cool mean temperatures but have a cost at warm mean temperatures.
2D and 3D visualizations of archosaur jaw muscle mechanics, ontogeny and phylogeny using ternary diagrams and 3D modeling
Summary: Case studies presented in this paper use ternary diagrams, a tool used in multiple scientific disciplines, to visualize spatial relationships of muscles across ontogeny, evolution, and muscle mechanics in archosaurs.
Phylogenetic analysis of adaptation in comparative physiology and biomechanics: overview and a case study of thermal physiology in treefrogs
Summary: Analysis of treefrog thermal physiology with the Ornstein–Uhlenbeck model of adaptation shows that increasing cold tolerance was key to successful colonization of the temperate zone.
Summary: A cardiovascular heat exchange framework (CHEF) that integrates biophysical concepts with direct measurements of physiological data in the field to identify physiological mechanisms of heat exchange and energetics of thermoregulation.